Relays- Understanding, Diagnosis and Testing Relayed Circuits-Pt2

[@rickrogers2649]

Hi Matt. I'm retired now after 42 years as a mechanic. I worked on heavy trucks then switched to elevators. Dealt with relay logic elevator control circuits for many years. This was spot on like all your videos. THANK YOU for sharing your knowledge with us and for reminding this old mechanic that it's good to be retired : ).

[@JonathanGarcia-eg2ey]

I don’t see how anyone can dislike this man. Hands down the best automotive YT’r for troubleshooting. Solid content.

[@SchrodingersBox]

Thanks man. Scannerdanner is better than me but I think I cater better to DIY’s than professionals.

[@tubetime39]

@@SchrodingersBox true, I'm diy'r and found ScanDan 1st, now you. I also spend some time in Colorado, by the way. Aurora, at daughter & family's , but first trip was back in '73. 5 1/2 yrs of doing deliveries '89 to '95 in Co. Den, Springs, Boulder, Ft Collins & Greely. Love Colorado. Denver has gotten to big for me. My barber in Aurora said after 45 yrs (2023) he's retiring and moving out. But Colorado otherwise, #lovingit

[@sonyyoung1036]

You are one of the best teachers on car electrical circuits on KZbin. Keep it simple even though the topic is not. At 8:20, you helped me understand relays with more than 4 terminals. Thanks

[@SchrodingersBox]

Glad to help!

[@DJDevon3]

Great diagnostic. You broke down that issue perfectly. Bravo. You said you only have a basic understanding of electrical diagnostics but obviously you don't give yourself enough credit. You are easily on an intermediate to advanced level. If you can diagnose a bad combination switch (light stalk) then you're definitely not a beginner. Beginners don't even know how to use a multimeter to it's fullest potential and you whipped right through voltage and resistance testing. The only thing wrong you did in this series is not properly evaluating your own skill level. You might think you only have a basic understanding but isn't that always the case? Everything seems basic when you know what you are doing. ;)

[@hunkledrog]

Thank you so much for both relay videos. I've been trying to get my head around how relays work for years, and finally the control side (reasoning and understanding side) in my brain activated the load side(common sense side) to allow me to finally "get it" within 5 mins of watching your 1st video

[@jarinwilson9539]

Absolutely brilliant! 9/10, I start at the relay(if applicable). The main differentiation for your diagnoses you want to make at the relay is this....load side fault or control side fault. That is extremely important and very useful. Every step in diagnostics should point you in a direction and if it happens to be the same direction as previous tests have indicated, you are more than likely headed in the right direction. In a matter of minutes, you can easily erase variables that do not pertain to the condition. To this day, this is one of your best videos Matt, congrats my friend.

[@SchrodingersBox]

Thanks bro! One of my better ones huh? What- the ball joint video didn't do it for ya lol? As you stated, every step should point or substantiate a direction. It is why I have said before, in a logical methodology, you are ALWAYS right even if you're "wrong". It's a beatiful thing, for those who get it!

[@jarinwilson9539]

Schrodingers Box It is in fact a beautiful thing...Haha, the ball joint video was good but of course I already knew how to do that particular job so it did not pertain to me. I completely understand a majority of your viewers are not professionals so it is valid for them which is the great thing about youtube. There really is a psychology/methodology behind automotive repair and unfortunately some people need to see a shrink, lol. Thank god you are not one of those people.

[@2011spaceage]

I have to say, I really enjoy your method of explaining how things work.

[@santiagoescalambre8116]

thank you again Matt...I spent sufficient time watching your part 1 n 2 relay videos n I am proud to tell u that now I truly understand how relays work..God bless u more...

[@SchrodingersBox]

+Santiago Escalambre I just now came across this comment Santiago!! That's awesome, I am sure you are even better with relays and electrical now than when you wrote it

[@nickwilson1476]

I learn so much from this channel. Thank you for taking the time to make these videos. They are very very good!

[@SchrodingersBox]

+Nick Wilson Thanks for watching!!

[@billygtrr34]

I learned so much from your videos that must to watch them a few times so won't miss anything, please keep doing videos!

[@stevenwatson3496]

Dude, this video is brilliant (along with part one). I understood about 85% of this before hand, but this really connected the dots for me. Thank you!

[@SchrodingersBox]

Glad to complete the circle!!

[@justinsmith623]

I’m continually impressed by your videos. You are also the only other person besides myself to use the term “in lieu of” in normal conversation. One of the guys I work with had to look it up when he read one of my emails. 🤣

[@SchrodingersBox]

Hahaha I guess now that you mention it, I don’t know anyone I can think of who uses that term lol

[@ncsarola]

Fabulous video! My understanding of relays finally clicked, no pun intended! Thank you so much. Trying to be a 2%.

[@SchrodingersBox]

Great job!

[@antegas]

Muchas gracias! A pesar de ser en ingles los entiendo claramente. Aprecio todo su esfuerzo. Dios lo bendiga desde Venezuela y nunca deje de colocar sus enseñanzas

[@jawojnicki]

Question for Matt: My wife's Chrysler T&C 1998 van uses a "solid state" type relay rather than a coil type. Could you do ( or do you have) a vid explaining how this type of relay works? Also, is it possible to test these without special equipment, like anything other than a DVOM? Thanks for this awesome series and keep them coming! WARNING for all viewers of this vid: While Matt's 2 part series on relays is fantastic and honestly, the BEST explanation of relays I've ever seen, PLEASE understand that not ALL headlight circuits (or any relayed circuits) are necessarily this simple. I have a Subaru Forester S, 2001, and both lights failed simultaneously last winter. Fortunately, I found ultra cheap (like 8 bucks) pdf file factory shop manuals on ebay, so I have the actual wiring diagrams for my car. In my car, the HL switch actually closes the ground circuit to BOTH the HL (load) AND the HL relays' control coils. In addition, the POWER side of the relay control coil is switched by the ignition switch (only HOT in "RUN"). Most cars don't require ignition switch to be on to operate HLs, but if you have a Subaru, I almost guarantee yours does. In my situation, you have THREE, not just one, switched locations in the circuit that could have been bad. Diagnosis could be done using Matt's method, but would have been quite a bit more difficult, since even in a working state, you'd have NO continuity to ground or power at rest on EITHER side of the relay control sockets in the fuse box. I respect Matt very much, but in my experience, the 8 dollar shop manual is worth it's weight in gold for the wiring diagrams alone! They've saved me SO much time. Incidentally, the issue turned out to be the ground wire from HL switch connector to the HL connector was burned and part of the connector melted. I got a new connector at the junkyard for ONE dollar. Unfortunately, had to spend 12 bucks on a special tool to get the pins out of the connectors, but still, was a fun repair!

[@bradybell6129]

"8 dollar shop manual " Where can you get this?

[@lawnmowerman-hf7tw]

nothing like real-life experience to drive a point home ... even though i had watched this video a while back, today i assumed that a clicking relay was a good relay and went on to waste about an hour checking other stuff. finally came back inside, re-watched this video, performed this SIMPLE, EASY, QUICK, DEFINITIVE relay test and determined that although the relay had continuity through the load side when energized, it was not passing current. never again will i think that a clicking relay is a good relay !!! great videos ... good camera work and i love the way you combine the DEBOK with actual cases. keep up the great work !

[@SchrodingersBox]

Excellent lesson! In fact I know I have one and I think even 2 times I have caught a nonfunctioning "clicking" relay on camera in my videos. A lot of people think I am wasting time checking continuity on a relay that I power-up, but we know for a fact it is a bigger time waster not to do that!!!

[@daleabono3616]

This was so awesome to find. Explained better than I have ever seen.

[@ThunderbirdRocket]

Very helpful ! I learned lots of new things . You explain things very well ; and the illustrations make the concepts crystal clear !!

[@JuanRodriguez-cm1rx]

Ive been watching all your teachings and I have learn a great deal, thank you so much , I am so seriously wanting to learn more , about how to test and Diagnose all electrical, I know the mechanic all ready .

[@movingupautodiagnostics8645]

Learned a lot with this series. Thanks Matt.

[@victormiesner7804]

Vic here(shade tree ass hat) just want to thank you for sharing your knowledge,you a good man!

[@incognito8386]

Another masterpiece. Now I have the confidence to tackle my no brake light problem tomorrow.

[@michaeljohn8905]

Great stuff thank you it is just cemented the information I have been reading I have tackled and eight pin relay which is a lot easier now that I have seen this and tested it. Thank you very much for this helpful video liked and subbed will share with the guys at my shop.

[@labodiesel7443]

Thanks Matt for your teaching skills

[@daddy14172722]

Thanks!! you have been a great help on helping me learn on troubleshooting electrical problems and solving it.

[@fieldsofomagh]

These are very informative videos both for the novice and experienced.Even though I have never used a Power Probe, it is a very versatile tool,especially for the novice where it is very easy to do a straight short on the main power lines.As the Probe will cut out in this situation ,it prevents an under hood barbecue.It behaves like the RCD on the house mains.From experience,the main contacts can be closed but due towear and pitting, no real contact is made.

[@eyesalooking]

Good point.

[@xristosmaglaras7077]

Just an EXCELLENT explanation....KEEP doing this...

[@SchrodingersBox]

xristos maglaras Thanks man, many more of these to come!

[@curlymyhero]

Thx again 4 your time! In this video u essentially worked BACKWARDS electronically (like the old dayz) to find the trouble which eventually was the headlight switch. The process of elimination... although I like yur way better even though it's a bit more complicated.

[@rickkimble8634]

Great hands on tutorial !!!!!!!!!!!!!

[@SchrodingersBox]

Thanks Rick. Hand-on is the way to go.. you can read wiring diagrams and watch videos all day until you turn blue it it isn't til you actually put it to application that it finally clicks. Ha! Clicks! Get it? This video is definitely a case where I learned more myself by making this video than I have learned cumulatively from everything I have studied in the past!

[@patriciacurzi3879]

This is good stuff Matt. You are top shelf.

[@tubetime39]

Thank You ! Just signed up to website. Why not at $3.49/mo ! Lots to learn. Have loan ( & ins !! As it sits 12 months now) on 2015 Promaster Van no one wants to work on with wiring issues. Another promaster owner told me dealership (Dodge, Chrysler) told him to come get his they couldn't fix his wiring problems.

[@SchrodingersBox]

man I would totally jump on it!!

[@stanleygavin9903]

Really well done!

[@nickayivor8432]

KNOWLEDGEABLE Schrodingers box Sharing what you know with us Thank you. Tutorial loved it video great from the start to finish 👏 👌 👍 Take care and have a great day Schrodingers Box From Nick Ayivor from London England UK 🇬🇧

[@gonzgarr1592]

great teaching on how a 4 prong relay works thanks

[@nedvlt1767]

BRILLIANT GENIUS TEACHER

[@alaster33]

Wow amazingly helpful , before I watch this video the only knowledge I had of a relay involved switching the Batten from your hand to the next runners hand 😂 now how to find the relay switch responsible for my AC blower , heated seats, reverse light and wing Mirror controls , which all went down together after having to recharge the dead battery on my 2003 Audi TT ... someone mentioned there is no relay for the blower on the TT , then somebody said they found a whole box of relays under the bonnet somewhere , any insight on that would be more then welcome 🙏 , at least I’m not rushing out to buy a blower motor now thanks to your great way of teaching and live examples kindest wishes

[@SchrodingersBox]

Thanks man. I always appreciate those who try to improve their understanding of electrical. It didn't come easy to me!!! I had to spend many hours on my own studying it.

[@alaster33]

I can get that , I recon because you learn all this with hands on real life experience, your self , you have a very clear step by step way of teaching this very complex subject... I am still wondering where how to find my relays , can you point me to any videos you have done on how to locate the main relay switches , so far I have only found one in the engine bay by the large air filter on the back of the firewall passenger side ??? Thanks again for your videos man you rock

[@remotaurog]

Thanks for your videos,fixed my central locking,didn't need to replace any parts,contacts inside the actuator were rusty.

[@alejandrovijil2211]

It was definitely helpful,hermano!!!

[@DENicholsAutoBravado]

I did understand relay operation before this, but now I can actually use the information beyond testing the relay! :) I repeated myself out of excitement. Deleted that. :)

[@SchrodingersBox]

Yes the ability to diagnose a relay is one thing, but being able to use a relay socket as a diagnostic port is a whole new level of efficiency. This is soooooo much easier than testing at the connector or fuse box in most cases and sure as HELL beats laying on the floorboard under the dash and steering column!

[@techsavantlove]

Some comments on Comments (part 1 and part 2): Randy Jones makes an excellent point (video part 1)about the inclusion and importance of the diode on some relays. The resources that I've linked talk about the purpose of the diode. Stuzman52 wrote an EXCELLENT piece (video part 1) about why the diode is there and what it does. Gene Hensley: Most of the links I posted below discuss the usage of the 5 pin relays. Keep in mind, MANY times a 5 pin relay will be installed on a car, but that the 5th terminal is not actually used for anything. But, sometimes the 5th pin IS used. Of course, you'd have to check your wiring diagram to be sure, but when replacing a relay, it is easiest to just get a direct replacement for whatever is already there. Emmanuel Munoz made a good note about testing the coil resistance. That subject (testing a relay) is covered in some of the links below also. Billy R made an excellent point, to use a test light when initially testing the input and outputs of a relay, to limit current.

[@tanalee229]

Super videos. Thanks so much!

[@techsavantlove]

HEY!!! Isn't it about time for another mailbox segment? I am in need of a good belly laugh, and the bathrobe and pipe would definitely do it for me. :) And I'm also ready for some more caustic comments towards the people who keep running out of gas so they replace their muffler.......

[@SchrodingersBox]

Lol, yes I'm working on it now... I have to be in one of those weird moods though. But I did fix that scantool issue with the trans am, have some more updates on past projects, and will have a few other surprises.

[@foxdmulder]

Great video, Informative and educational. Only downside is most of these practices only apply to vehicles up to 2004. After this manufacturers started using CAN networks. Ecu's and modules control lighting directly.

[@SchrodingersBox]

This is very true- I should have pointed that out. In fact, even on the horn circuit, much of the ":relays" nowadays are CPU controlled switches to allow things like the sound of the horn beeping when you lock the doors remotely, etc. The complexity is far beyond what is covered in this video however the video at least gives a foundation for learning the basic operation.

[@syetube1]

Absolute LEGEND....Thanks....

[@musaalgheriany8917]

Nice helpful video, thank you so much

[@sergionewsome6657]

Hellow Sir, first I want to thank you for your content, very insightful and entertaining. I have a question about a mistery with my car's headlight electrical system. So first of all, I have a 2000 Acura TL that I lost both headlights all of the sudden, both low and high beam. So I checked both fuses and relays, and the bulbs, they are all fine. I have a ect 3000 from power probe, as well as the power probe. Ive traced both harnesses right and left and on the passenger side, there seems to be some kind of ground fault. The right headlight relay show 12v on the control side but no ground, the fuse is also dead, but not blown. when I trace my ground wire im lead to the chasis of the car, than the sound stops when I go passed it. Ive tested all my grounds to the battery, but they are all good, the wireing all seems to be fine but when I try to trace an open circuit, it leads me to the inside of the car, but than it just takes me in a circle. I cant seem to figure for the life of me what could be the issue, any thoughts, Im a DIYer but consider myself to be a decent mechanic and understand automobile electricity pretty good, Im at a loss. What would cause the ground to be absent? I thank you in advance and hopefully you can give me some insight.

[@SchrodingersBox]

Thanks for the compliment. Obviously you only have ground on the control side when the headlamps are switched on. If you aren’t seeing that happen the issue is with the switch. I don’t believe I have ever seen a headlamp system that was power side switched except on a 1957 Buick. Simply provide a ground side to the relay and see that it operates confirming a switch issue. Also since you have the power probe, just send 12V to the load side and make sure it lights the headlamp- this confirms you only have a control side issue and not a load side issue. Most systems have a constant 12V load side power at all times but I have seen some that only have the load side power with key on. Either way it doesn’t matter- 12V to the ground side of the load should light the lamp. If it doesn’t then test for the voltage at the socket and if it isn’t there, your ECT will be needed to find the open.

[@sergionewsome6657]

Thank you, I actually did that and was able to get the lights to come on, but when I replaced the switch, it didn't solve my problem. I'll continue to try tracing I just hope its not my drivers multiplex control unit. according to the wiring diagrams thats where the high beams seem to lead me. Not sure if its worth it at that point, everything on this acura seems to be more expensive than any other car I've owned. Again, thanks for the prompt reply! @@SchrodingersBox

[@littlebeargaming8267]

Great video. Wish you had covered a diode protected relay. With a diode protected relay, power has to be applied to the right pin in the load side, right? Usually, pin 86.

[@SchrodingersBox]

Not sure which pin number but yes- diodes are basically electronic switches activated by current.

[@techgood]

Amazing thank you Schrodingers

[@SchrodingersBox]

Glad you liked it!

[@techgood]

Schrodingers Box this weekend I am planing to troubleshoot my ML350 starter and its wiring issue, already removed starter found it dead, took it to a rebuild shop, they tested it too, so got a rebuild one, but still have to fix starter relay, its not getting power, hope fuse some where. this car has few circuits, starter relay should get power from circuit 15 then activate circuit 50 (starter solenoid) most likely shorted solenoid kill some fuse somewhere - i am wondering why 5 year old car have bad starter? your video definitely will help me to fix my electrical issue Thanks Again.

[@nhitc6832]

@5:30 I'm having trouble understanding why you would put 12V at the fuse? Wouldn't there already be 12V at the fuse because you said the fuse is good and there is no open before the fuse. If that's the, all you had to do is simply measure if there is 12V at the switch. It seems to me that putting 12V at the fuse is just unnecessary?

[@942doc1]

Spectacular video. I came here from watching another one of your vids (crank no start isuzu) and now I have a solid understanding of 4 & 5 pin relays. Thank you 🙌... (did you ever work in a shop before by any chance?) Did you ever get your ASE certifications? Just curious as to how you got to your level.. (definitely seems like your up there) 😳

[@SchrodingersBox]

thanks so much. I am a DIY- just learned this stuff fixing neighbors cars over the years.

[@942doc1]

@@SchrodingersBox that's awesome. (I'm a firm believer that the best way to learn things is to dive head first into them & learn on your own) looks like it definitely worked for you 💯

[@sgtdrinkho]

Awesome video keep them coming!!!

[@SchrodingersBox]

Will do! This one is one of my favorites. Doing diagnostics from the relay box often keeps you from having to crawl under a car!

[@oibal60]

Watched part 1. Boss!

[@daleabono3616]

At 6:04 how do you know which wire to poke at with 12v?

[@daleabono3616]

Nevermind. Find continuity from the fuse.

[@techsavantlove]

Tech tips; Here are a few thoughts about relays on cars; Much of the time, the relay will be referred to as the standard "Bosch 5 pin relay" type. It is an industry standard. They are made by many companies, and are easily available anywhere. But the "Bosch style" is not always used. Other types and designs are used as well. But the Bosch style is used on most modern cars. The 5 pins have universal meanings. Each terminal has a specific universal number, whether the relay is labeled or not. The linked articles cover that in detail. The pins are also positioned in a universal way so that you can see which pin does what, by looking at the bottom of the relay (the pins, or blades). In other words, if you memorize (or use a picture of) what each pin is used for, based on it's position and angle, that will be the same on every Bosch style 4 or 5 pin relay. And the numbering is also universal (i.e. Pin 30 is the high amp input, pin 87 is the high amp output, etc.) I THINK, but I am not positive, that the color scheme for all 5 wires is universal. You'd need to research that, but I'm fairly sure that each of the five terminal wires on a proper socket would use the specific colors, but I have also seen reference to sockets being sold that don't have the proper color wires attached to the proper socket hole, so be careful with that. The sockets, with a few inches of pigtail wiring are available at any auto parts store. When replacing a relay, it is important that the relay have equal or greater current ratings as the original. Usually, both the primary and output sides will be rated, for example, something like this: 20/30 It means 20 amps rating on the input coil and 30 amps rating on the output. Of course, having 20 amps on the primary side virtually never happens on cars (it would negate the whole point of using a relay), but the relay does need to be rated to handle the proper output (switched) current. Relays rarely fail. When they do, it is usually because the switching contacts get pitted and corroded, and basically just "wear out". The other typical failure mode would be an open in the coil side (input). Most of the time, when a relay wears out or fails, it is due to the wearing out of the contacts in normal use, OR the output circuit is carrying more current than it is supposed to, which obviously means there is a problem in the switched (output) circuit. The Bosch style relay is cheap, about 3 to 6 dollars. It is important to buy a decent quality one. On many relays there will be a diagram, and it will include the letters NO and NC, meaning Normally Closed and Normally Open. Matt covers that very well. It is not very common for pin 87A to be used. Sometimes it is used, but not a lot. Even so, MANY cars will use a 5 pin Bosch style relay even when only 4 pins are being used. The articles linked below cover that. The input side (the coil) can be power side switched or ground side switched. It will work fine either way, but power side switching is by far the most common. As Emmanuel Munoz mentioned, the coil side can (and should) be tested for resistance. An open on the coil would obviously show infinite resistance. When testing the output side of a relay using a meter or test light, it is very possible for the test to show a good relay, when it really isn't. It only takes a trickle of current for an ohms check across closed contacts, or a small amount of current to power a test light, but the contacts can be so pitted or corroded that they can't handle any significant current, as it is originally designed to. I.E. it might test ok for resistance when closed, or it may power a test light fine, but when used to carry the high current that would be typical (20 amps or so) it just can't do it. So tests for relays can be a little tricky. The purpose of the bypass or "quench" diode that Randy Jones mentioned is covered in some of the links below. But none of them will probably explain it any better than Stuzman does. Many cars use several identical Bosch style (or other types) relays. My car has 4 next to each other in the Power Distribution Box, all with the exact same Chrysler OEM part numbers. So for testing purposes I could switch two of them and see if the suspect one works OK. Some "flasher" circuits (like turn signals) use a connector that will accept a 4 pin or 5 pin Bosch style relay, but don't make the mistake of putting a relay where a flasher belongs. Very, very bad things can happen. Excellent videos, Matt, as always.

[@SchrodingersBox]

Fantastic feedback as always. Once again I learn more from the comments than I did researching for the video. I probably need to get the comments first before I do a video next time lol

[@mtrltoolman]

i think this video need a 3rd part to complete the vision on the relays . thank you matt for the great explanation.

[@SchrodingersBox]

toolman talal Agreed- given the new information in many of these comments, I agree more detail is needed on 5 pin and diode relays.

[@zaproyal]

Freakin awesome as always!!!

[@SchrodingersBox]

zaproyal I know. I amaze myself as well.

[@cobraninetysix3883]

Another great video! Here's a question. How would you determine the load side from the control side of a stuck closed unmarked relay. I suppose checking for resistance would be a start? I had a stuck closed relay on a fuel pump that wouldn't shut off. Took an educated guess and swapped the relay with a new one and it fixed the problem. That was when I was a 98%'er

[@SchrodingersBox]

Cobra Ninety Six I would find this out by checking inside the vehicle where the relay goes and probing for the side that has no power until you initiate a control/switch. That would be your control side... then you can just refer that information back to the relay

[@attissotogbo5399]

Thanks for teaching and good job. You have done a big thing. Do you have a training class?.

[@SchrodingersBox]

Lol this is my training class. I am just a Do-it-yourselfer, not an instructor.

[@joaquinpasillas6358]

Very nice video, while I was watching your vid being a flat rate diag tech I was thinking of your diag steps one step I though you were going to due was just bypass the headlight switch all together since you had the connector in hand and you knew what circuits came in with voltage and what circuit or term was the output of the switch another thing I think is so very important when doing this type electrical diag work is to make sure u load test circuits I use a 9007 headlamp bulb that a that I rigged up i can interchange alligator type clips or pin type term, maybe your next series should be about the importance of load testing circuits and how to do voltage drops factory pin point tests tests for open, shorts to power and shorts to ground but not resistance within circuits.

[@genesmith2355]

I understand everything you're saying, thank you for this video, one question where are you getting a low voltage from.

[@SchrodingersBox]

Low voltage? what are you referring to exactly?

[@jcstevegigs]

Great lesson! Thanks! I was the 600th LIKE!!! (Love when that happens)

[@michaelhanglow5051]

Awesome information

[@genehensley767]

GM someimes uses a bias voltage I believe on control side of a relay maybe you can explain that to us thank very nice videos part 1 & 2 I learned a lot

[@Garth2011]

Great review. Very interesting. No pun but, your + appears more like an X on the white board. Best to get the horizontal - flat so it doesn't confuse folks it's an X.

[@techsavantlove]

CORRECTION: I was in error in describing the current rating of the coil and the output circuit (contacts). I said that the numbers, such as 20/30, referred to the coil and output current ratings. That was wrong. A rating such as 20/30 means the relay is rated for 20 amps through the Normally Closed contacts and 30 amps through the Normally Open contacts. Sorry for the error.

[@whitetiger8652]

Another very informative video. Where did you get your automotive training at?

[@whitetiger8652]

White Tiger Have you ever watched Dan Sullivans videos on Relays and diagnosing the entire system with voltage drop as well as using the Load Pro Leads for a digital voltmeter? I have a set of them and for the most part it seems to be an excellent tool just as is the Power Probe. I just watched a video for the new Power Probe 4. It has some nice additional features.

[@Sandbag1300]

Outstanding! You take a potentially complex problem and through a logical plan approach make it so simple. How much $$ did you end up saving that person?

[@WasimAkram-dv1ch]

Nice topic. Sir Can you please make a video on diagnosis and understanding of an alternator. How it works and how to test and how to full field an alternators and other stuff like that related to alternators. Thanks

[@SchrodingersBox]

Wasim Akram Thats a good idea, duly noted. Alternator testing is actually not quite as easy as most people think. There is computer control of the alternator in modern vehicles to prevent overcharging and failure with this can actually cause a no output from the alternator even if it is good!

[@WasimAkram-dv1ch]

Schrodingers Box​ thats​ exactly why i have requested you to through a video on that too 

[@techsavantlove]

OK, I'm on somewhat of a roll here with suggestions............sorry if I'm overdoing it. Although it is not in any way a repair or diagnostic video, I think many of your hardcore viewers would enjoy seeing a video where you do an exhaustive inventory of all the performance mods you have made to the Trans Am.

[@SchrodingersBox]

Actually I will be doing some videos on performance mods- both good and bad ones, in the future. But I want to focus on the practical applications first as that is critical to then understanding the variations created by performance mods. That way maybe idiots will stop removing MAF screens and the like because their shallow thinking dictates it must improve airflow by removing restriction.

[@Airman..]

badass keep goin man

[@yazmo109]

nice information thx you very much

[@SeusankerKissoon]

Could u check voltage on d load side of arelay with d volt meter on ohms scale

[@SchrodingersBox]

You would only be able to see continuity of the ground that way, you can’t measure voltage like that.

[@charlesgould8436]

Was that an old buick headlight switch?:) hey man, thanks.!

[@billyr9840]

Clicks! Yea we get it! LOL! Something's wrong with you dude! LOL! Great set of vids Matt! I can see that oscilloscope coming! I'm full of suggestions this morning, so here's another, you should warn people that when they are probing sockets/connectors not to push their probes down into the connecter because it will spread them and they will not make contact when you reinstall the relay or what ever you happen to be testing. I know you weren't right! LOL!

[@santiagoescalambre8116]

+Billy R, I agree with your suggestion.. that's another good feed back..thanks man...

[@billyr9840]

Where The Hell You Been? LOL ! You got to get something going Dude, been harassing ScannerDanner by watching his older vids and posting! LOL! Only kidding, I know your busy with your real job! If I don't hear from ya, Have a Great THANKS GIVING! GOD BLESS!

[@SchrodingersBox]

Lol actually I have been building a new computer so I can process HD vids, you will see on my next release maybe this weekend.

[@geraldhunsinger3672]

You ain't no scanner Danner he forgot more than you know

[@sirsweetness8332]

Good video

[@bradsellers1912]

Hi I'm having a problem with my 2001 Saturn L200. All the interior lights r blinking and security light at the same time also gas and temperature gauge goes up and down. I have a video please watch it called (Saturn Lights Blinking) Thx any info would be appreciated

[@SchrodingersBox]

Its either a dead or not-charging battery or loose battery connection. Easy

[@cendiacocri]

Brad Sellers that happens a lot to me, and in most cases is a loose ground at either the taillights or the headlamps. Having a bad ground makes actually a serial connection between the blinklights and the other circuits (brake or headlights, parkinglights), thuus making them blink, but at a lower voltage, all the lights are dimmer because they share power with the blinks. So for the future check for a good grounding point.

[@brentlybyers]

Gem.

[@SchrodingersBox]

I think so too- one of the most important videos on the channel!! I use these concepts all the time.

[@JahanZeb1976]

Great to watch the second part of the series. A few days back I worked on on of my friend's Toyota Corolla 2004 headlights. Head light circuit is a bit confusing sometimes due to the new technology involvement in the newer models. Here is the video link. Give a look please. Regards, kzbin.info/www/bejne/sJDXl2ajnriFi5I

[@mtrltoolman]

good video my friend .

[@monoribalazs]

cheap aftermarket immobilisers uses basic closed, 12V to open relays. If is immo on, it breaks the ignition, or fuel pump circuit. (on cranking no start the first suspects are these stuffs)

[@67275gtb4]

Excellent video, however… There’s no way he found a headlight switch for Saab at the parts store. 😂

[@DJDevon3]

He bought 2 new headlights on the advice of whom? An auto parts store? See this is the crux of the problem. It should be illegal for auto parts stores to give automotive advice. It's a conflict of interest. I think the culture of parts changers begins and ends with automotive parts store. They profit from instigating and catering to bad habits in the same way a drug dealer works. It's actually in their best interest to get you hooked on your bad habit, feed your habit, and keep you coming back for more. They take advantage of people to the point it's now a multi-million dollar business model.

[@santiagoescalambre8116]

+DJDevon3,you are right. remember there are many crooks out there. instead of helping novice people they ripped them..

[@jimnicosia5934]

Just put some volts on them & see if they click.

[@SchrodingersBox]

Yep a I do that too however I also check for continuity on the load side as well. just because it clicks does not mean there is continuity and in fact I have 3 videos that show exactly that happening

[@tytyyerbury]

The people that are saying that you're a great teacher must be your friends because that's the only way somebody would say that. And I'm not sitting here watching this alone I'm watching this with some other men and they're saying the same thing I am

[@SchrodingersBox]

well then I just have hundreds of thousands of friends and you must spend lots of time with “other men”. I can help people who lack basic fundamental cognition. I only provide information in a way that even remedial people can understand but not those below remedial. This is why you think a relay works if it clicks. smh.

[@nickayivor8432]

What do you call PRODIGY and INTELLECTUAL AND SUBSTANTIAL add one more KNOWLEDGEABLE the answer is SCHRODINGERS BOX My teacher Thank you very much helpful information video tutorial amazing video brilliant thank you. God bless you and all your family around you and take care and have a great day SCHRODINGERS Box From Nick Ayivor from London England UK 🇬🇧

[@SchrodingersBox]

Thanks for the compliment my friend from across the pond!!